1
|
Silva LT, Junior RS, Teixeira de Carvalho TX, Moutinho Pataca LC, Dias Heneine LG. Analysis of antibodies avidity for Tityus serrulatus scorpion venom in antivenom production and its potential for application as a potency test. Toxicon 2023; 236:107315. [PMID: 37827265 DOI: 10.1016/j.toxicon.2023.107315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 09/26/2023] [Accepted: 10/09/2023] [Indexed: 10/14/2023]
Abstract
Antivenoms are the only specific medication for neutralizing toxins present in venom of animals such scorpions and snakes through antigen-antibody binding. Several analyses are carried out throughout its production in order to ensure the quality and effectiveness of the antivenom that will be administered to the patient. One of these is the potency assay, which is performed to assess the ability of antivenoms to neutralize the toxic effects of the venom injected in mice. The substitution of in vivo for in vitro assays such as ELISA has been presented by other authors, bringing several advantages such as the reduction in the use of animals, in costs and in the duration of the assays. However, the avidity index of antivenom antibodies determined by ELISA has not yet been applied for this purpose. Therefore, the objective of this study was to evaluate the avidity of sera from hyperimmunized horses with crude Tityus serrulatus venom, a scorpion species associated with the most serious accidents in Brazil, and its potential for application as a potency test replacing the in vivo assay. The avidity ELISA proved to be interesting for monitoring the binding strength of antibodies produced by horses in hyperimmune plasma production programs. It was possible to verify oscillations in antibody avidity that occurred along the immunization cycles, differences between novice and veteran horses, maturation of antibody avidity, and correlation between avidity index and antibody titre. Similar results were obtained for crude venom and purified Ts1 toxin. In addition, the avidity ELISA apparently demonstrated potential for application as a potency test in the initial stage of antivenom production. However, more studies are necessary.
Collapse
Affiliation(s)
- Lucas Tadeu Silva
- Ezequiel Dias Foundation - Funed, Belo Horizonte, Minas Gerais, Brazil
| | | | | | | | | |
Collapse
|
2
|
Chieffi PP, Zevallos Lescano SA, Rodrigues E Fonseca G, Dos Santos SV. Human Toxocariasis: 2010 to 2020 Contributions from Brazilian Researchers. Res Rep Trop Med 2021; 12:81-91. [PMID: 34040480 PMCID: PMC8141392 DOI: 10.2147/rrtm.s274733] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 04/26/2021] [Indexed: 01/18/2023] Open
Abstract
This is a review of the published contributions made by Brazilian researchers between 2010 and 2020 on the natural history of human toxocariasis and the effects of human toxocariasis on nonhuman paratenic hosts.
Collapse
Affiliation(s)
- Pedro Paulo Chieffi
- Department of Pathological Sciences, Santa Casa Medical School, São Paulo, Brazil
| | | | - Gabriela Rodrigues E Fonseca
- Department of Infectious and Parasitic Diseases, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | | |
Collapse
|
3
|
Sierra MF, Ricoy G, Sosa S, Colavecchia SB, Santillán G, López CM, Mundo SL, Sommerfelt IE. Humoral immune response of pigs infected with Toxocara cati. Exp Parasitol 2020; 218:107997. [PMID: 32946882 DOI: 10.1016/j.exppara.2020.107997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 08/14/2020] [Accepted: 09/13/2020] [Indexed: 11/16/2022]
Abstract
Toxocara cati is one of the causative agents of human toxocariasis. Serological methods are used for diagnosis in paratenic hosts like humans but the humoral immune response triggered by this parasite is unknown. We characterized the humoral immune response to T. cati excretory-secretory antigens (TES) in pigs as animal model during the acute and chronic stages of infection. ELISA and Western Blot techniques were used to determine antibody response. Pigs were experimentally inoculated with 100,000 infective Toxocara cati eggs. Blood was collected at 7, 14, 21 and 28 days post-inoculation (d.p.i.) to assess the acute stage of infection and 90, 120 and 180 d. p.i. for chronic stage analysis. ELISA showed values higher than the cut-off of specific IgM and IgG at 7 d. p.i. with significant differences at 0 and 7 d. p.i. for IgM and at 14, 21 and 28 d. p.i. for IgG in the acute stage. Higher and stable levels were detected in the chronic stage. Western Blot showed bands from 102 to 38 kDa detected by specific IgM and IgG. More immunogenic bands were identified by specific IgG. In the chronic stage of infection a band near 31 kDa was the only band detected by IgM until 150 d. p.i. Specific IgG recognized bands between 102 and 31 kDa. This study demonstrates how the humoral immune response evolves in the acute and chronic stages of infection and provides evidence on the role of the pig as a paratenic host of T. cati.
Collapse
Affiliation(s)
- Maria Florencia Sierra
- Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Salud Pública, Av. Chorroarín 280, C1427CWO, Buenos Aires, Argentina.
| | - Gerardo Ricoy
- Servicio de Inmunología Parasitaria. Departamento de Parasitología, Instituto Nacional de Enfermedades Infecciosas Anlis "Dr. Carlos G. Malbrán", Av. Vélez Sarsfield 563, C1282AFF, Buenos Aires, Argentina.
| | - Sonia Sosa
- Servicio de Inmunología Parasitaria. Departamento de Parasitología, Instituto Nacional de Enfermedades Infecciosas Anlis "Dr. Carlos G. Malbrán", Av. Vélez Sarsfield 563, C1282AFF, Buenos Aires, Argentina.
| | - Silvia Beatriz Colavecchia
- Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Inmunología, Av. Chorroarín 280, C1427CWO, Buenos Aires, Argentina.
| | - Graciela Santillán
- Servicio de Inmunología Parasitaria. Departamento de Parasitología, Instituto Nacional de Enfermedades Infecciosas Anlis "Dr. Carlos G. Malbrán", Av. Vélez Sarsfield 563, C1282AFF, Buenos Aires, Argentina.
| | - Clara Maria López
- Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Salud Pública, Av. Chorroarín 280, C1427CWO, Buenos Aires, Argentina.
| | - Silvia Leonor Mundo
- Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Inmunología, Av. Chorroarín 280, C1427CWO, Buenos Aires, Argentina.
| | - I E Sommerfelt
- Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Salud Pública, Av. Chorroarín 280, C1427CWO, Buenos Aires, Argentina.
| |
Collapse
|
4
|
Paller VGV, Besana CM, Valdez IKM. Dot enzyme-linked immunosorbent assay (ELISA) for the detection of Toxocara infection using a rat model. J Parasit Dis 2017; 41:933-939. [PMID: 29114122 DOI: 10.1007/s12639-017-0914-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 03/28/2017] [Indexed: 11/24/2022] Open
Abstract
Toxocariasis is a zoonotic disease usually caused by dog and cat roundworms, Toxocara canis and T. cati. Detection and diagnosis is difficult in paratenic and accidental hosts, including humans, as they cannot be detected through conventional methods such as fecal examination. Diagnosis therefore relies on immunological methods and molecular methods such as enzyme-linked immunosorbent assay (ELISA) and Western Blot, which are both time-consuming and requires sophisticated equipment. In the Philippines, only a few studies are available on Toxocara seroprevalence. Therefore, there is a need to adapt methods for serodiagnosis of Toxocara infection in humans for the Philippine setting. A dot enzyme linked immunosorbent assay (dot-ELISA) was standardized using T. canis excretory-secretory antigens. Test sera were collected from laboratory rats (Sprague-Dawley strain) experimentally infected with embryonated eggs of T. canis and Ascaris suum as well as rice field rats naturally infected with Taenia taeniaeformis and Nippostrongylus sp. Optimum conditions used were 20 µg/ml antigen concentration and 1:10 serum dilution. The sensitivity, specificity, positive, and negative predictive values were 90% (95% CI 55.5-99.7%), 100% (95% CI 69.2-100.0%), 100% (95% CI 66.4-100%), and 90.9% (95% CI 58.7-99.8%), respectively. Dot-ELISA has the potential to be developed as a cheaper, simpler, and more practical method for detection of anti-Toxocara antibodies on accidental hosts. This is a preliminary study conducted on experimental animals before optimization and standardization for human serum samples.
Collapse
Affiliation(s)
- Vachel Gay V Paller
- Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines Los Baños, Los Baños, Laguna Philippines
| | - Cyrelle M Besana
- Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines Los Baños, Los Baños, Laguna Philippines
| | - Isabel Kristine M Valdez
- Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines Los Baños, Los Baños, Laguna Philippines
| |
Collapse
|